Inspiratory flow limitation (“IFL”) is a common component of sleep-disordered breathing. IFL is established by the presence of flow limited breaths. A conventional technique for detecting/identifying IFL breaths, or flow limited breath(s), using supra-glottic pressure and airflow signals has previously been developed. For example, a breath is classified as IFL when there is no increase in airflow associated with a 1 cmH2O drop in supra-glottic pressure. This is referred to herein as the “gold standard.” However, the conventional technique requires catheterization of the subject's pharynx to obtain supra-glottic pressure. Thus, the conventional technique is invasive.